One is the steady gaze of the eyes and of the mind, which helps one in penetration.

Another thing is losing everything else from one's sight except the object through which one wishes to penetrate; and that comes by sufficient interest in the object of penetration.

But the third thing, which helps most, is losing for the moment the thought of one's self. When one's body and mind are not before one, it is then that one has the proper insight into things one wishes to know and understand.